the invitation

Invitation to Seminar Talk
A generalized relative entropy and a BCS
functional without artificial boundary
Andreas Deuchert
IST Austria, Klosterneuburg
Host: Laszlo Erdös
In the first part of this talk we consider a recently introduced generalized relative entropy for bounded and not
necessarily compact linear operators on a separable Hilbert space. Defined is this object by a limiting procedure that
resembles a thermodynamic limit. A natural question in this context is whether there exists a formula that allows one
to compute the resulting limit without going through the relatively complicated limiting procedure. We answer this
question affirmatively and provide a general formula for this limit. Under weak additional regularity assumptions on
the operators, we show that it takes a form that is particularly suited for explicit computations.
In the second part of the talk we use the relative entropy from the first part to define a version of the BCS functional
of superconductivity without artificial boundary conditions. We investigate this functional in the parameter regime
close to the critical temperature where Ginzburg-Landau theory is assumed to be valid and show that it is bounded
from below. A direct consequence of our lower bound are a -priori estimates for states with energy lower or equal
than that of a certain reference state. These bounds are a crucial ingredient for the derivation of Ginzburg -Landau
theory in our set-up.
Tuesday, October 25, 2016, 04:00pm
Seminar Room Big Ground Floor / Office Building West
Thi s invi tation is va lid as a ti cket for the IST Shuttle from a nd to Heiligenstadt Station. Pl ease find a s chedule
of the IST Shuttle on our webpage (note that the IST Shuttle ti mes a re highlighted i n dark green):
The IST Shuttle bus is marked IST Shuttle (#242) and has the Institute Logo printed on the s ide.
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